Controller for elevators.



C. W. WHEELER. l/*"GONTROLLER FOR BLETATGRS. Arruoniox Umb MAR. 1s.1907. RENBWBD my 16, mo,

1,1 12,745. Patented. oet-L.

3 SHEETS-SHEET l.

lilllillll C. W. WHEELER. CONTROLLER FOR ELEVATORS.

APPLICATION YLBD HAR. 18 1907. RENBWED MAY 1S, 1910.

zabemea om.;

gif i C. W. WHEELER.

CONTROLLER FOR ELEVATORS.

PPLIUATEON FILED 111111.15, 1907. RENEWED MAY 1s, 1910.

l 1 1 2,745.. Patented Oct. 6, 1914.

3 SHEETS-SHEET 3.

Clt

CLARENCE Vil. WHEELER. OF CHICAGO, ILLNOIS CONTROLLER FOR ELEVATORS.

intonaci.

Application led March 1S. 1907, Serial No. 362.5279.

To uit trimm it m n.1/ (concer/1 lle it known that i,tiniinxcnlllVnnnLnu, a citizen of the United States, and a resident ol (lhieago,Cook countyillinois, have iuventcd certain new and useful improvementsin Controllers for Elevators, ci which the tollowing` is a tull, clear,and exact description. auch as will enable others sliilled in the art'`to which it appert'ains to maite and use tie same.

lily invention relates to electric controllers and has particularreference to improvements in starters and controllers Yfor the motors ofelectric elevators.

".lfne object ot my invention is to provide an in'iproved and.'-iimplified starter and con-- troller 'for electric motors; and withthis object in view. my invention consists' fimoerallj.` in the noveldevice hereinafter described and iiiarticularly pointed out in theclaims. Bly invention will be more, readily understood by reference tothe accompanying drawings, forming a part of thisl speciiication and inwhichvw Figure l is an elevation ol a Iewitch board equipped with ancchai'iiem embodying my invention: Fig'. ll is a side elevation oic vaportion ol the mechanism illustrated in Fig. l, the saine comprisingmeans iiorvarying` the. rei-iistance in the circuitJ ol the startinglield, and in several auxiliary circuits; Fig. lil is a detailillustrating the in xans for operating Said mechanism; Fig'. lV is asection on the liney #i---i ot Fig. 3; Fig. V is a side, elevation o lanother portion olf my device. the same constituting;` mechanism forautoimitically controlling the speed regnlatingj field and tor varyingtheresistance in the circuits oi several auxiliary correlated ciicuiis;Fig. Vl is a de .ail pla a view of one oli the contact members shown inFig. V; and Fie. Vil ie a diagram, illustrating the layout of anelectric system equipped with my novel automatic cmi'troller7 thelat-ter beingl also shown in diagram.

before ,stated my invention has reference to starte-rs and centrollersfor motors oi electric. elevatorru or the like, wherein the Startingswitch is at considerable distance from 'the motor switch board.' rilhe.switch board iS. in best practice, heated near the motor and it il; uponthis that l locate the i indicates .cnient'ly near j., ferries allSpeeiieatcn of Letters Patent.

Patented Renewed May 16, 1910. Serial No. 5Gl,'71.9.

ot thc-motor operatingmechanism. with the exception oi' the startingswitch. which is located upon thc car: and au. automatic limit switch,3, located near and operated by the cable windingdruni. to operitc asafety brake. This latter forms no part oli the present invention. henceis oni).v indicated conventionally in the dra wings. lvpon the Switchboa rd are located two m guet operating switchen7 -l and 5, only one ofwhich is in operation at a time. to govern the direction oi'5 rotationol the armature; a line or potential Switch.y (l, which cleses thecircuit ol the motor and of the controlling mechanism. simultaneouslywith the closing of one ot the a'toremcn'tioned orafi-ating; 4switches;an aruniture :speed accclerationr device operated by a solenoid. l,which is excited instantaneously with the closing oi the line switch, 6;a shunt' `field regulatingl device for increasing or decreasing 'thespeed of the armature. and operated by a solenoid, ti, energized onlyalter the speed azcelerating device has operated throughout its limits;aud an automatic magnetic switch, 9, Jtor tinallyY elosinthe circuit tothe solenoid 8. These parts may be arranged in any convenient` mannerupon the switch board, i, and none of them will require detaileddescription. with the exception of the armature i-ipeed accelerat'ing`device and the shunt liel'tl regulating` device.

Ris before mentioned, the solenoid l' is cnergixed upon the closiiig ofone of the switches il er :3, and the switch l; that is, when saidswitches are closed, they close the circuit to said solenoid. Thesolenoid 'l' is thus responsive to the closing and opening of the lineswitch, 6; hence the armature speed accelerating' device7 operated bysaid solenoid. if; also directly responsive thereto.

lO indicates the lsolenoid core, the speed of which is controlled by avacuum dash pot, il. This dash pot, not only prevents sudden or unevenaction ot the core. hut also serves to quickly rcturi. `the core and theparts connected thereto, to initial position when the solenoid isdeenergizcd. .it right angles to the cere il) is an ofaillatory shaft,

1'2, jonrnaled in brackets, lC'l,ii13on the switch beard, l. This shaftis suitablyv connected to the core 1t), so that reciproeatimi of saidcore will impart rotary oscillatory motion to the shalt. ln Figs. llland V l have illustrated "l: and pinion connection between said cole andshalt. yThe rack, l-l7 is lA I] miams preferably ma de of a separatepiece, and sci. into a groove formed in the side of the core and thepinion, 15, which meshes therewith is rigidly secured to the shaft 12.

Besides the pinion, 15, the shaft 12 also carries a plurality of cams,16, occupying diti'erent radial positions. These cams operate a likenumber of levers, 17, which are adapted to cut out resistance in a shuntcircuit oi the armature starting field, which waakens said field, toincrease the speed oi1 the armature. As the cams 1G occupy dif- `ferentradial positions on the shaft, the levers 17 are operated successsively,thus speeding up the armature gradually. For a better understanding ofthis portion of the device and its details, attention is directed i,iarticularly to Figs. l and ll of the drawings. Flach lever 17 ispivoted upon a bracket, 18, secured to the board, 1, and is equipped atone end with an anti-friction roller, 1.9, preferably of insulatingmaterial, to engage its respective cam 16. The opposite. ends of thelevers 17 are provided ivit-h yielding contacts 20 to engage a likenumber of contacts 21 upon the switch board, 1. The levers 17 areconnected to the line leading to the starting field, Whereas thecontacts 21 are connected to a return line, resistances 22 beinginterposed between said contacts. in other Words, the contacts. 21 andinterposed resistanees 22 are arranged in parallel with the circuit ofthev` starting lield. When the motor armature is at rest the contacts 2Oare held out et engagement with the contacts 21; but yas soon thesolenoid 7 is energized by closing of the switches 2, et or 5, and ,6,the levers are operated successively to cut out resistance in the shuntcircuit, reducing the current in the starting iield. Hence it will beseen that the armature starts into operation with a field of fullstrength, which lie-ld is gradually reduced in strength as the armaturespeed increases.

Besides the pinion, 15, and the cams 16, the shat't 12 also carries oneor more cams .223 adapted to operate a like number ot lovers to closeauxiliary circuits or to vary the resistance and hence the currenttherein. ln the drawings l have shown three such vers; one lever, Q4,increases the resistance in the circuit oi' the magnet `which operatesthe switch (l, another, Q5, increases resistance in the circuit ot thesolenoid 7, and another, 2u, 'closes the circuit to the magnet switclil, which in turn closesl the circuit to the :,'peed regulating solenoid8. The levers, 17, "l, 5, and QG, are all loosely mounted in respec Aebrackets and but slight er"- i, is required to operate them, as there isno trictional contact between the parts as y is the usual case with moetvariable re-l nce devices. llene-e it will be seen that ref' "tance totl uio-romeni' of the cero I thus far, takes place when the switch lever2 is in the position shown in full lines in Fig. VH, and the speed atwhich the armature runs when the lever is in this position will bespoken of hereinafter as the normal running speed. lf it is desired torun the armature at a greater Ispeed, the lever 2 is thrown into theposition shown in dotted lines in said figure. This may be done at onceupon starting the machine, or the operator may wait until the armaturehas assumed its normal running speed. In either case, however, the speedvarying solenoid 8 will not be excited until after the armaturevaccelerating or starting solenoid 7 is actuated throughout its limits.To this end the magnet switch 9 is interposed in the circuit ol" thespeed varying solenoid 8. As has been mentioned, this switch is actuatedonly at the end of the positive stroke ofthe solenoid core 10, afterwhich, if the switch 2 is in the position noted in dotted lines, thecore or" the solenoid S will be actuated.

27 indicates the core of the solenoid 8, and 28, a vacuum dash pot whichcontrols the movement of the core "27' in the same mauner the dash pot1l. controls that ot the core 10. At right angles to the core 27 is ashaft, 29, rotatably mounted in brackets,y30, secured tothe switchboard, l, andvconnected to and operated by the core Q7 in a mannersimilar to the connection and the operation of the core 10 and the shaft12 hereinbefore described.Y rl`he shaft Q9 carries a number of cams ilwhich operate a like number ot levers 32 to vary the resistance in thecircuit of the high speed field of the armature. 'lhe variableresistance device, of which the levers 32 are a part, operate similarlyto the armature speed accelerating device; however, as the variableresistance in thisI circuit in .series with the field, additionalresistance is thrown into the circuit by the operation ol the levers,instead of cutting out the resistance as in the aforementioned case.lBesides the cams 31 the shaft 2S) also carries a pllu'ality ot' cams 3Gfor operating a like number of levers for inserting resistzuice intovarious solenoids. lV have illustrated three such levers, 353, 3l, aud$3.1. The lever 33 throws further resistance into the circuit ot themagnet which operates the switch (i, the lever Slt Virol 's resistanceinto the circuit ot' thev magnet ol the .switch il; and the lever 35throws resistance into the circuit of the Solenoid S at the cod ot' thestroke et its core 27.

Ver the sake of a better understanding of llulu-reindescribed preferredtorni of my device und its operation l will describe a ino-.or systemincluding the saine. )referline :connects it with the line o.

ring to Fig. VH, the main line is indicator. at o--o. Assuming that thecurrent enters at a., it will pass through the line a to the permanentfield coil pf, thence through the line a to the line wire o. This muchof the circuit is always complete, whatever the position otv theswitches. lllhen the switch lever 2 is moved to the position shown infull lines in Fig. VH, the current will pass from, a, through line Z/ tothe switch 3, thence through line 7)" to the contact n of 'the switch 2,thence. to the Contact n, and through the line 5"' to a magnet P of theswitch 5. This closes the switch 5, estalilishing the connectionshereinafter described.. From the magnet P the current passe to another arm of the switch 3, thence through line s to one Contact of the lever24. This is now in the 4'ioziditioii of least resistance. The current.then passes through line a to the magnet Q which closes the switch 6.The closing: ot this switch is si- .multaneous with thtl closing of theswitch From the magnet Q. the circuit is traced and completed hv theline connected to the contact 3%-, thence bv liu-e S, then by line Smand a. to terminal connection with line Zi.

By closing the :-1\.'itches 5 and G, connections are cstahlisied betweenthe line and the armature and the starting tield, which starts thearmature in motion. rlhe line to the startingfield and the armature maybe traced through the lilies u. and r: to the contact Z, through switchto contact Z', thence through line to contact Z, thence through line cto the armature, returning through line (Z to contact point Z3, thenceto contact point Z4, through line rl to d, and thence through uw tostarting Held s j?. The. circuit is completed through line d4 to switchG whiclrconnccls said line to the main line 7) through contacts Z5 and ZAs before stated, the variable resistance device which regulates thestarting field.` and which is operated h v the solenoid T, is inparallel with the circuit of the starting held. llence, as thc core oithe solenoid is actuated, the strength ot the field is weakened to speedup the armature to normal running speed. In the diagrran'i. l haveillustrated the core as heine; lowered, when the solenoid isenerffrized.A This is done merely for the salte of clearness otillustration. The energization of the solenoid 7 taires place upon theclosing!- er" the switches 5 and 6 the circuit heine established throughline c and line e ro the solenoid. and from thence through cf* tocontact- 49 of the Switch G, which lVhen the plunger 10 reaches theliinit of its movement after the energizat-ion of the solenoid 7, theswitch lever 26 connects the contacts y) p', as shown more clearly inFig.

VII, As before stated, the,diagrain`of Fig.

v ll represents downward movement of the plunger l0 when the solenoid 7is energized, although in the actual construction as snown in Fig. lwhen the solenoid 7 is energized the core l0 is moved upwardly. W henthe contacts y) p are connected a circuit will be closed through themagnet of switch 9, beginning at tl c positive main and extenduingthrough con-.luctor o', contacts n and n2,

limit switch, magnet of which is connected h v the lever 34, contact 7X,lever 2G, contact p, and thence to the negati-ve main through the switch6. lllhcn switch,9 is operated the circuit is closed through thesolenoid S, which extends from the positive through conductor o', switch9, lever 35, solenoid 8, and thence to the neg: tive main through switcho. As soon as the solenoid 8 acts on its core i?? to more the saine thelevers and 34- are actuated to insert resistance in the circuits ot' theman nets ot the switch 9. After the plunger i?? has completed its strokethe lever is permitted to be actuated. to insert resisfance. in circuitwith the solenoid S. Less power is required to hold the solenoid coreafter it has completed its movementl than is required to start it :tromits initial position. Therefore resist-ance is not inserted in circuitwith the solenoids or magnet windings until after the pluugers orarmatures have conipletcd their strokes. By inserting resistances in thcsolenoid and magnet winding` circuits switch 9, conductor the heating ofthe .windings is reduced to a minimum and the current consumption isreduced. I `urthermore, when the current is cut otl from the controllingcircuits the parts are restored to initial position .more quicklybecause oiE less tendency of the magnets and soleiioids to hold theplunge'rs and armatures in attracted position because the strength ofthe magnet has heen reduced to a minimum. This is particularly importantwith respect to the rheostat solenoid 7, which by having the resistanceinserted in circuit with it is maintainer! only sutlicie'ntly strong tohold the plunger up, hut when the current is cut ott' the solenoid willimmediately let Lg'o of the plunger so that thc starting resistance canhe reinserted without any delav whatever. lt` should also be noted thatthe resistance. controlled hiv the lever 24- is inserted in the circuitcontaining,r the magnets O and l), so that when the current is cut olfthe reversing switches are immediately restored to initial position. Assoon as the solenoid 7 releases its plunger 'l0 the starting resistanceis reinserted and the r'.\.-

ksistance controlled hy the lever 25 is not cuty out until all ornearliall of the starting; resistance has been reinscrtcd. As beforestated, much less current is required to hold the plunger in itsuppermost nosition than to start it from its initial position and thearrangement issuch that on the release of the ii o ililunger 'l0 `itcannot be pulled up again by thc solenoid 7 until the resistancecontrolled by the lever 25 has been cut out. At this time all thestarting resistance has been reinserted, and since the resistancecontrolled by lever is cut out thc solenoid 7 could get suflicientcurrent to again effect the cutting out of the starting resistance ifdesired.

VThe last part of the rotation of the shaft l2 closes the. gap betweenthe contact points p and n', which permits the relay 9 to be thrown intoaction'as soon as the switch lever 2 is thrown into engagement with thecontact n2. The closing of the line at these two points completes thecircuit to the magnet of the lrelay 9, which closes the line throughsolenoid 8 and the high speed field les. The variable resistanceoperated by the solenoid 8 is in series with the high speed coil,therefore I construct this portion of the device so that the operationof the solenoid 8 will increase the resistance insaid field, otherwisethe action of the solenoid'S is similar to that of the solenoid 7. Theshaft 29, which is actuated by the solenoid S is equipped with camswhich operate the resistance varying levers 33, 34, and 35 as beforementioned, one of which throws resistance into the circuit of thesolenoid 8 by the completion of' the stroke ot' its core, and an-l otherthrows resistance into the circuit of the automatic magnetic switch 9.

To reverse the direction of rotation of the arma-ture it is butnecessary to throw the lever 2 to the opposite side of the switch box 2(in the car). This will throw the magnet O of the switch 4 intooperation instead 0f the magnet P of the switch 5. Otherwise theoperation is identical with that hereinbetore described. rlheI lay-outof' thc system illustrated is such that but one of the switch magnets Oor I can be operated at a time. To insure the fopening of one switchbefore the other is closed I prefer to connect the switches bv a rocklever 87. By reterencc to Fig. I it will be seen that as the magnet ofone switch is energized and the switch operated, the other switch willbe. thrown open by the lever 37.

llaving thus described my invention what I claim as new and desire tosecure by Letters Patent is:

l. In motor controlling apparatus, the combination with startingresistance, of automatic means for controlling the same, an electricmotor having three field windings, one being permanently connectedacross the mains, and another being in parallel with the startingresistance, resistance in circuit with saidthird field winding, andmeans for controlling said last named resistance to vary the strength ofsaid third field winding.

2.- In motor controlling apparatus, the

combination with an electro-magnetic rheostat, of an electric motorhaving three field windings, one being permanently connected across themains. and another being connected in pa allel with the startingresist-- ance of said rheostat, an electro-magnetic` rheostat for thethird field winding of said motor, and circuits and connections for ef'-fecting the automatic and successive operation of said electro-magneticrheostats.

3. In motor controlling apparatus, the combination with anelectro-magnetic rheostat, of an electric motor havingthree eldwindings, one being connected permanently across the mains, and anotherbeing in-parallel with the starting resistance of said rheostat,electro-1nagnetic reversing switch mechanism for the motor, anelectro-magnetic rheostat for the third field circuit, anelectro-magnetic main line switch, an electromagnetic relay forcontrolling the third field circuit rheostat, a manual switch forcontrolling directly said reversing switch mechanism, saidelectro-magnetic relay and said electro-magnctic main line switch, andcircuits and connections for effecting the automatic operation of thereversing switch mechanism, main line switch and the first namedelectrdmagnetic rheostat when the manual switch is in one position, andwhen in another position the additional operation of the electrdmagneticrelay and the third field circuit rheostat after the rst namedelectro-niagnetic rheostat has performed its operation oi cutting outthe starting resistance and the second field winding.

4. In elevator motor controlling apparatus, the combinationwith anelectric motor having a field winding, of starting resistance for saidmotor, switches for controlling said resistance electro-magnetic meansto positively close said switches, field resistance,

electro-magnetic mechanism for controlling said resistance to vary thefiedstrength of the motor, a master switch for controlling the saidelectro-magnetic means, a relay interposed between said' master switchand said electro-magnetic' mechanism, and means for preventing saidelectro-magnetic mechanism from operating unt-il substantially all ofthe starting resistance has been cut out.

, 5. In a device ot the class described, a motor having three fieldcircuits, in com bination with two variable resistance devices, onevariable resistance device being associated with each of two of saidfield circuits, means for operating said variable resistance devicesautomatically and successively, an elevator car switch for controllingsaid operating means so as to effect the operation of one variableresistance device when in one position and of both successively andautomatically when in another position, and a relay interposed bet-wcensaid car switch and one or said operating means.

6. rIhe combination with an electric motor Cn v Il f3 having a fieldwinding and an armature circuit, a variable resistance device for thearmature circuit, ot' electromagnetic mechanism for operating saidresistance device to elect the acceleration ot' the motor at starting,an additional resistance devi-ce 'for the iield circuit, additionalelectro-magnetic mechanism for operating thi` last named resistancedevice to eiiect an increased speed oit the motor or a decreased speedthereof, an elevator car switch for controlling both v of saidelectromagnetic mechanisms and having an intermediate speed position anna tast speed position, and circuits and connections to eiiect asuccessive and automatic operation of the variable resistance device forthe armature and the variable resistance device Jfor the Held circuit inthe order named.

T. In a device of the class described, the combination with a motorhaving a slow speed `held circuit and a high speed field circuit, ofstarting resistance in parallel with the-slow speed lield circuit, speedresistance in circuit with said high speed field circuit, anelectrmnagnet and switches for cutting out said starting,r resistanceand said slow speed held circuit, an additional elect-roinafrnet andswitches for controllingr said speed resistance by inserting the same incircuit with said high speed lield ci 'cuit or cutting it out therefrom,an elevator car switch having two speed positions, and circuitsandconnections ellecting the cutting out ot the starting resistance andthe slow Speed field circuit when the switch is in one position and 'foreilccting' the operation of the second named clectromagnet and switcheswhen the said car switch is in its other positioin'but permitting theautomatic increase of speed to maximum to take place onliY aitcrsubstantially all thc starting rcsis'tance has been cui out,

S. ln a device oit the class dcscrihed, the combination with a rockshaft, of a plurality ci.: cams thereon, switches positively operated bysaid cams, starting resistance controlled h r said switches, an electricmotor, a solenoid and plunger with connections for operating said rockshaft, additional resistance connected to the motor ield winding, anadditional rock shaft, cams thereon.` switches operated hy said cams,solenoid plunger and connections for controlling said field resistance,an elevatorcar switch connected to said solenoids, and circuits andconnections for eiecting the successive and automatic operation ot saidselenoids and parts operated thereby to effect an acceleration the motorto intermediate speed and increase oi speed to full speed when the carswitch is in one position and to eliect the operation ot only the tirs-tnamed solenoid when the car switch is in slow speed position.

9 in niotor controlling apparatus for elevators, the combination with anelectric inotor, oi' sectional starting;- resistance therefor,electro-magnetic means tor cutting out said resistance, reversing switchmechanism, a car switch for controlling said reversingA switch mechanismand said electro-magnetic means, additional resistance in circuit withthe field winding", an electro-magnet 'for controlling said additionalresistance, a rela",Y interposed between the car switch and the lastnamed electro-magnet, and in fans tor ciiecting:y the automatic andsuccessive operation oi' cutting out the stai-timar resistance andinsertingl the lield resistance when the ar switch is in a predeterminedposition.

l0. l'n motor controllingl a 'lor elevators, the combination with anelectric motor, of reversing` switch inecl anism thoreior, anelectro-magnetic rlicostat tor the armature circuit of the motor, a mainline potential switch, an elevator car switci, an additional magneticrheostat for the field circuit of the motor, and circuits andconnections Jfor effecting the simultaneous operation of the reversing'switch mechanism. and the main line potential switch, and alsoeii'ectingthe operation of the el( ro-magnetic rheostat ior the armaturecircuit of the motor to accelerate the speed thereof to an intermediatepoint and compelling` the cloctro-magznctic rheostat tor the heldcircuit to operate automatically after said first named rhecstat hassullstantially completed its operation.

1l. ln elevator motor controlling:v apparatus, the combination with anelectric motor, of reversing switch mechanism therefor, anelectro-magnetic rheosl'at tor the armature circuit oi' the motor, anelectro-magnetic main line potential switch, an elevator car switchhaving' a slow speed and a tast speed position for cach direction ofrotation of the motor, an electro-magnetic rheostat i'or the iieldcircuit oi' the motor, a relayv interposed between the elevator carswitch and the held rheostai', a switch associated with saidfirst namedrheostat 'for preventing the second named rheostat Vfrom operating untilthe first named rheostat has substantially completed its operation, andconnections hctween the car switch and said electro-niagnetic rheostatto eiiect the operation ot' the armature rheostat when the car switch isin Slow speed position and the operation ot' hoth the armature rheostatand the licld rheostat successively and autmnaticallv in the order namedwhen the car switch is in tast speed. position. n

l2. Vin elevator motor controlling apparatus. the combination ot anole/:tric motor` ol an electro-magnetir rheostat 'for the armaturecircuit ot said motor. electro-nrione!iiA reversing switch mcclmnism forthc motor, an electro-magnetic rheostat ior inserting' or withdrawing,`resistance from the shunt field circuit of the motor at will during` theoperation ot the motor, an electrmi-magnetic main line switch, a inanualcarswitch connected to said electro magnetic rheostat, electro-niaguctiereversing switch mechanism, and electro-niagiaftic main line switch; anelectrohmgnetic relay interposed between .said car switch and saidelectro-magnetic field rheostai, a switch associated with saidelectro-magnetic armature rheostat to prevent the operation of theelectro-magnetic field rheostat until after said armature rheostat hasoperated lo cut out substantially all the starting resistance, andconnections atiording;r the ci r switch two .speed positions in one ofwhich the armature rheostat only is operated and in the other of whichboth the armature rheostat and field rheostat are operated automaticallyand successively, the field rheostat being restored to initial positionand the motor slowed down to ntermediate speed when the car switch ismoved from its high speed position to its intermediate speed position.

' 13. In motor controlling apparatus, the combination with startingresistance, ot' automatic means i'or controlling the same, an

electric motor haring` three field windings, one being;h a shunt fieldwinding, connected across` the mains, and another being in parallel withthe starting,` resistance, resistance in circuit with the third field.vindiag, and means for controlling the field resistance to vary thestrength of said third field windi110'.

il. ln an elevator motor controlling system, the combination with anelectric motor having three field windings, one being an i independentshunt field circuit, another beingf connected to the startingresistance, resistance connected to the third field winding, starting,Tresistance for the armature circuit, switches connected to said startingresistance, cams for operating said switches, a rock shaft foroperatingv the cams, a solenoid and plunger for actuating said roel;shaft, reversing switch mechanism for the electric motor7 anelectro-magnetic main line potential switch, switches connected tosaid.`

field resistance, cams for operating said switches, a rock shaftcarrying said cams, an electro-n1agnet :t'or actuating said rock shaft,a switch preventing` the operation of said electro-magnets until all otsaid starting resistance has been cut out, a manual car switch havinetwo speed positions, in one of which the automatic cutting out or" saidstarting resistance is effected, and in the other of which the automatic(,)peration et said field resistance is eti'ected atter said startingresistance has been cut out, and an electro-magnetic relay interposedbetween said car switch and said electro-magnet tor controlling; thefield resistance, the field resistance being,Y restored to initialposition to effect the slowing down ot the niotor to intermediate speedwhen the car switch is moved from high speed position to inten inedia'espeed position.

In testimony whereof, I have hereunto set my hand, this Sth day' otliigiarch, 190i', in the presence ot two subscribing witnesses.

CLf-iRENCE lV. lVl-IEELER.

Titnesses H. S. AUSTIN, A. XV. NELSON.

